What tertiary activities are

When you are ill, you visit a doctor; when you need help with a legal matter, you go to a lawyer. You pay them for their special skills. Such skills, provided in exchange for payment, are services.

Tertiary activities are all of these service activities. They include:

• Production: the provision of services that are 'consumed' (used) directly, such as those of a doctor, teacher or plumber.
• Exchange: trade, transport and communication, which move goods, people and information from one place to another.

The output of tertiary activities cannot be weighed like grain or steel. It is measured indirectly, through the wages and salaries paid.

The key difference from primary and secondary activities: tertiary work depends on specialised skills, experience and knowledge, rather than on production techniques, machines and factories.

In developed economies, most workers are employed in tertiary activities; in developing countries, a larger share still work in primary activities.